The Canadian Pneumoconiosis Reading Panel (CPRP) Study was discussed. THE CPRP was formed in 1984 to determine the current ability of physicians in all Canadian provinces who used the International Labor Organization (ILO) system to read chest X-rays and to develop a method of feedback that would encourage those physicians to achieve a uniform standard of reading. The panel selected 1000 test X-ray films from among more than 10,000 collected by the Ministry of Labor. Films were selected from three groups: male civil servants, 40 to 70 years old, who had never been occupationally exposed to fibrogenic dusts; workers exposed to silica (14808607) or asbestos (1332214) who developed silicosis or asbestos; and workers with other industrial lung diseases. The films were randomized, divided into lots of 30, and sent every 2 weeks in rotation to each of 26 physicians participating in the study. The films were then returned to a central depository. Feedback was provided at quarterly intervals. The feedback indicated whether a reader was within 1 minor category of the group average ILO category for small opacities on each film or over or under the category. Preliminary results for 16 participants indicated that 31% of the films were over read, 4% were under read, and 65% were in agreement with the group average.